Effect of key mixture parameters on flow and mechanical properties of reactive powder concrete

The main objective of the study presented in this paper was to examine the effect of key factors, which affect the performance of reactive powder concrete (RPC) mixtures. Firstly, an optimum sand grading was selected based on the maximum compressive strength and acceptable flow of a typical RPC mixture keeping the proportions of its ingredients constant. Then, keeping the sand grading and fiber content constant at their optimum levels, a total of 27 mixtures of RPC were selected for study by considering three levels of the three key factors namely water-to-binder ratio, cement content and silica fume content, according to a 3(3) factorial experiment design. The dosage of superplasticizer for each mixture was optimized to keep the flow in the desirable range of 180-220 mm. The performance of the selected mixtures of RPC was evaluated in terms of compressive strength, modulus of rupture and modulus of elasticity. Statistical analysis of the experimental data indicated the significant effect of sand grading, water-to-binder ratio, cement content and silica fume content on flowability and mechanical properties of RPC. The regression equations were obtained for mechanical properties of RPC mixtures in terms of the key mixture parameters, which can be utilized to optimize the proportions of RPC mixtures within the ranges of the mixture variables considered in this study. (C) 2015 Elsevier Ltd. All rights reserved.